1. Field of the Invention
The present invention relates to a windshield wiper device for automatically wiping off raindrops, snow, mud, dust and such adhering to the surface of the windshield of a vehicle.
2. Description of the Related Art
Generally, a windshield wiper device has at least one windshield wiping unit comprising a pivot holder attached to a panel forming the body of a vehicle, a pivot shaft supported for turning on the pivot holder, a wiper arm having a base end part fixed to an outer end part of the pivot shaft projecting outside from the pivot holder, and a wiper blade assembly having a wiper blade and connected to the free end of the wiper arm. The wiper arm is oscillated to wipe the surface of the windshield of the vehicle with the wiper blade.
A windshield wiper device proposed in JP-U No. 60-261 has a pivot shaft retaining mechanism for preventing a pivot shaft supported for turning on a pivot holder from coming off the pivot holder. This pivot shaft retaining mechanism employs a washer. The pivot shaft is provided with an annular groove, a metal washer or a wave washer is put on the pivot shaft and a C ring is fitted in the annular groove of the pivot shaft with the metal washer or the wave washer in contact with an end surface of the pivot holder. The metal washer or the wave washer retains the pivot shaft in place and limits the axially downward movement of the pivot shaft relative to the pivot holder. Thus the pivot holder is fixed to the body of the vehicle, and the pivot shaft projects from the surface of the body, the wiper arm is attached to a free end part of pivot shaft, and a wiper blade assembly is connected to the free end of the wiper arm. The pivot shaft is restrained securely from axial movement relative to the pivot holder and from falling off the pivot holder.
The pivot shaft having a considerably long part projecting outside from the surface of the body of the vehicle is subject to various exposure to external impact forces, and it is possible that the pivot shaft maybe forced to project further from the body to cause damage when the body is deformed by a collision of the vehicle against an obstacle. For example, there is a possibility that the projected pivot shaft strikes against and damages a lower part of the windshield of the vehicle.